Holley 2 bbl progressive carburetor. Model 2305, 350cfm. I've had this for a long time, but never used it but once for a period of a couple of weeks. It was rebuilt about 15 years ago. It is in excellent condition, but it has been in a box for over 10 years. All I can say is it worked perfectly when I had it installed. Very smooth from idle on up. The reason i decided it was not ideal for me is the lack of a fast idle. On my daily driver, that was irritating. It includes an adapter from the 2 bbl to a 4 bbl manifold. I can also include both a Holley Renew kit 37-749 and/or a Holley TrickKit 37-1536 depending on your needs and how much you want to spend. $350 obo (plus shipping) gets all of it.